Exemplary embodiments of the present disclosure relate to a turbine blade, and more particularly, to a turbine blade including a cooling channel through which cooling air is passed and a swirl portion provided at an entrance of the cooling channel so as to form a swirl flow for cooling air.
In general, a gas turbine refers to a kind of internal combustion engine which mixes fuel with air compressed at high pressure by a compressor, burns the mixture to generate high-temperature and high-pressure combustion gas, and injects the combustion gas to rotate a turbine. That is, the gas turbine converts thermal energy into mechanical energy.
In order to construct such a turbine, a plurality of turbine rotor disks each having a plurality of turbine blades arranged on the outer circumferential surface thereof may be configured in multiple stages such that the high-temperature and high-pressure combustion gas passes through the turbine blades.
Gas turbines have been increasing in size and efficiency leading to an increase in temperature of a combustor outlet. A turbine blade cooing unit is commonly employed to withstand high-temperature combustion gas.
In particular, a structure may have a cooling channel through which cooling air of a turbine blade can be passed. The structure passes compressed air extracted from the compressor rotor to the cooling channel, in order to utilize the compressed air as cooling air.
As illustrated in FIG. 1, the turbine blade 10 includes a root unit 1, a blade unit 2 having a leading edge 4 and a trailing edge 5, and a platform unit 3 provided between the root unit 1 and the blade unit 2. The blade unit 2 has a plurality of cooling channels 7 formed therein, and the plurality of cooling channels 7 communicate with a cooling air entrance 9 and are divided through a plurality of partitions 6. Each of the cooling channels 7 has a plurality of turbulators 8 to generate turbulence in the cooling air flowing therein.
However, the turbine blade 10 is limited to the turbulators 8 for increasing heat transfer efficiency in the blade unit 2, and cooling units for the root unit 1.
That is, since the weight of the blade unit 2 rotating at high speed concentrates on the root unit 1, the root unit 1 is required to have a high level of strength.
When the gas turbine is driven, a considerable amount of heat is continuously transferred to the platform unit 3 and the root unit 1 through the blade unit 2 exposed to the high-temperature combustion gas. Thus, as illustrated in FIG. 1, when cooling units suitable for the platform unit 3 and the root unit 1 are not provided, the strength of the root unit 1 decreases to a significantly low level. As a result, the root unit 1 may be damaged.